My Radio was running continuously on external power but one day it died. I checked the power supply on another Radio and it was fine. I suspected that it may be the internal connection to the power input so I inserted a battery, and whoof my Q3 went up in smoke. So I’ve replaced that but it hasn’t got the Radio working again, and I’m wondering what the best sequence of replacement of items should be assuming (per the SB3 C16 and C20 capacitors) that there is a most likely failure mode. Any advice? I can solder capacitors, but that U2 power amplifier looks beyond my capabilities.